MM-14246 - Plugin framework: support transactional semantics with KV Store (#10634)

* MM-14246 - Plugin framework: support transactional semantics with KV Store

Rename old, new variable names

Moving New function to the bottom

* Made CompareAndUpdate sync, updated tests

* Removed going through channel in CompareAndSetPluginKey

* Inserting new key when oldValue is nil to KVCompareAndSet

* Updated error text to include CompareAndSet

plugin/api.go

@@ -459,6 +459,16 @@ type API interface {
 	// KVSet will store a key-value pair, unique per plugin.
 	KVSet(key string, value []byte) *model.AppError
 
+	// KVCompareAndSet will update a key-value pair,
+	// unique per plugin, to the given new value if the current value == the old value.
+	// Inserts a new key if oldValue == nil.
+	// Returns (false, err) if DB error occurred
+	// Returns (false, nil) if current value != old value or key already exists when inserting
+	// Returns (true, nil) if current value == old value or new key is inserted
+	//
+	// Minimum server version: 5.12
+	KVCompareAndSet(key string, oldValue, newValue []byte) (bool, *model.AppError)
+
 	// KVSet will store a key-value pair, unique per plugin with an expiry time
 	//
 	// Minimum server version: 5.6

plugin/client_rpc_generated.go

@@ -3490,6 +3490,37 @@ func (s *apiRPCServer) KVSet(args *Z_KVSetArgs, returns *Z_KVSetReturns) error {
 	return nil
 }
 
+type Z_KVCompareAndSetArgs struct {
+	A string
+	B []byte
+	C []byte
+}
+
+type Z_KVCompareAndSetReturns struct {
+	A bool
+	B *model.AppError
+}
+
+func (g *apiRPCClient) KVCompareAndSet(key string, oldValue, newValue []byte) (bool, *model.AppError) {
+	_args := &Z_KVCompareAndSetArgs{key, oldValue, newValue}
+	_returns := &Z_KVCompareAndSetReturns{}
+	if err := g.client.Call("Plugin.KVCompareAndSet", _args, _returns); err != nil {
+		log.Printf("RPC call to KVCompareAndSet API failed: %s", err.Error())
+	}
+	return _returns.A, _returns.B
+}
+
+func (s *apiRPCServer) KVCompareAndSet(args *Z_KVCompareAndSetArgs, returns *Z_KVCompareAndSetReturns) error {
+	if hook, ok := s.impl.(interface {
+		KVCompareAndSet(key string, oldValue, newValue []byte) (bool, *model.AppError)
+	}); ok {
+		returns.A, returns.B = hook.KVCompareAndSet(args.A, args.B, args.C)
+	} else {
+		return encodableError(fmt.Errorf("API KVCompareAndSet called but not implemented."))
+	}
+	return nil
+}
+
 type Z_KVSetWithExpiryArgs struct {
 	A string
 	B []byte

plugin/plugintest/api.go

@@ -1862,6 +1862,29 @@ func (_m *API) HasPermissionToTeam(userId string, teamId string, permission *mod
 	return r0
 }
 
+// KVCompareAndSet provides a mock function with given fields: key, oldValue, newValue
+func (_m *API) KVCompareAndSet(key string, oldValue []byte, newValue []byte) (bool, *model.AppError) {
+	ret := _m.Called(key, oldValue, newValue)
+
+	var r0 bool
+	if rf, ok := ret.Get(0).(func(string, []byte, []byte) bool); ok {
+		r0 = rf(key, oldValue, newValue)
+	} else {
+		r0 = ret.Get(0).(bool)
+	}
+
+	var r1 *model.AppError
+	if rf, ok := ret.Get(1).(func(string, []byte, []byte) *model.AppError); ok {
+		r1 = rf(key, oldValue, newValue)
+	} else {
+		if ret.Get(1) != nil {
+			r1 = ret.Get(1).(*model.AppError)
+		}
+	}
+
+	return r0, r1
+}
+
 // KVDelete provides a mock function with given fields: key
 func (_m *API) KVDelete(key string) *model.AppError {
 	ret := _m.Called(key)